This epidemiologic study aims to examine the etiology and outcome of neonatal brain hemorrhage, particularly its commonest form, intraventricular and periventricular hemorrhage (IVH). The study will take place in three Level 3 newborn services which together serve 85% of all low birthweight (Less than 2000g) infants born in a three county area of Central New Jersey that has 12,000 annual live births. Ascertainment of IVH will be by ultrasound in life and by autopsy in infants who expire. All infants 2000g or less will be screened with cranial ultrasound at four hours, 24 hours and seven days of life. Infants over 2000g will be screened with a neonatal neurological screening examination, and infants screening positive will also be examined by ultrasound. Data will be collected on antepartum, intrapartum and early neonatal events, including a maternal interview on pregnancy exposures, for assessment of their relationship to presence or absence of IVH. The epidemiologic characteristics of early IVH (first 24 hours) and later IVH will be separately examined. Infants over 1500g with IVH will be matched to controls on race, birthweight and nursery of care. All cases and controls, as well as all infants under 1500g, will receive a neurodevelopmental examination at age two years. The presence or absence of neurodevelopmental abnormalities and sensory deficits will be assessed and examined in relation to presence or absence of neonatal ultrasound abnormality.